Add remaining design tokens value types

Problem/Motivation

We have shipped #3531854: Add a Design Tokens & CSS variables API in 11.5 and 12.0, with those Design Tokens value types plugins: Dimension, FontFamily, FontWeight, Number and Typography, because they were enough to check the API proposal.

There are more in the upstream specifications:

• Color : https://www.designtokens.org/tr/2025.10/format/#color
• Duration: https://www.designtokens.org/tr/2025.10/format/#duration
• Cubic Bézier: https://www.designtokens.org/tr/2025.10/format/#cubic-bezier

And some more composite types:

• Stroke style: https://www.designtokens.org/tr/2025.10/format/#stroke-style
• Border: https://www.designtokens.org/tr/2025.10/format/#border
• Transition: https://www.designtokens.org/tr/2025.10/format/#transition
• Shadow: https://www.designtokens.org/tr/2025.10/format/#shadow
• Gradiant: https://www.designtokens.org/tr/2025.10/format/#gradient

Proposed resolution

Let's add the remaining plugins in https://git.drupalcode.org/project/drupal/-/tree/main/core/lib/Drupal/Co...

User interface changes

None

Introduced terminology

Not really. But I guess some concepts like "Cubic Bézier" will be new for some drupalers.

API changes

No, we are just adding plugins as PHP classes, without extending an interface or adding a service.

Data model changes

Not really. The new plugins will extend how design tokens data is stored inside the "scopes" proeprty of the config entity, but is not altering the config entity model itself.

Release notes snippet

TBD